import random
import string

def generate_test_cases():
    test_cases = [
        ("", 0, ""),
        ("abcde", 1, "bcdea"),
        ("abcdef", 3, "defabc"),
        ("hello", 5, "hello")
    ]
    
    # 生成随机测试用例
    for _ in range(5):
        length = random.randint(5, 10)
        password = ''.join(random.choice(string.ascii_lowercase) for _ in range(length))
        target = random.randint(1, length)
        expected = password[target:] + password[:target]
        test_cases.append((password, target, expected))
    
    return test_cases